Towards 1 Gbps/UE in Cellular Systems: Understanding Ultra-Dense Small Cell Deployments

By David López-Pérez, Ming Ding, Holger Claussen, Amir Hossein Jafari. IEEE Communications Surveys and Tutorials, 2015

482 citations recorded by the source corpus.

Today's heterogeneous networks comprised of mostly macrocells and indoor small cells will not be able to meet the upcoming traffic demands. Indeed, it is forecasted that at least a $100\times$ network capacity increase will be required to meet the traffic demands in 2020. As a result, vendors and operators are now looking at using every tool at hand to improve network capacity. In this epic campaign, three paradigms are noteworthy, i.e., network densification, the use of higher frequency bands and spectral efficiency enhancement techniques. This paper aims at bringing further common understanding and analysing the potential gains and limitations of these three paradigms, together with the impact of idle mode capabilities at the small cells as well as the user equipment density and distribution in outdoor scenarios. Special attention is paid to network densification and its implications when transiting to ultra-dense small cell deployments. Simulation results show that comparing to the baseline case with an average inter site distance of 200 m and a 100 MHz bandwidth, network densification with an average inter site distance of 35 m can increase the average UE throughput by $7.56\times$, while the use of the 10 GHz band with a 500 MHz bandwidth can further increase the network capacity up to $5\times$, resulting in an average of 1.27 Gbps per UE. The use of beamforming with up to 4 antennas per small cell BS lacks behind with average throughput gains around 30% and cell-edge throughput gains of up to $2\times$. Considering an extreme densification, an average inter site distance of 5 m can increase the average and cell-edge UE throughput by $18\times$ and $48\times$, respectively. Our study also shows how network densification reduces multi-user diversity, and thus proportional fair alike schedulers start losing their advantages with respect to round robin ones. The energy efficiency of these ultra-dense small cell deployments is also analysed, indicating the benefits of energy harvesting approaches to make these deployments more energy-efficient. Finally, the top ten challenges to be addressed to bring ultra-dense small cell deployments to reality are also discussed.

Subfields: Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/72dc88ad5663a3defa305ae5d2a72e0fa4695681

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Citations in the corpus

A Survey of Multi-Access Edge Computing in 5G and Beyond: Fundamentals, Technology Integration, and State-of-the-Art (2019, unknown): “mes, e.g., small-eNB on/off and frequency reuse, are of importance for guaranteeing the network performance. Finally, more sophisticated and practical propagation models are required in dense HetNets [279]. While users and eNBs are positioned in 2D planes in traditional networks and regular HetNets,”
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User-Centric Mobility Management in Ultra-Dense Cellular Networks under Spatio-Temporal Dynamics (2016, background): “Notwithstanding some compromises on practical feasibility, the above approximations provide the logarithmically increasing average rate tendency as densiﬁcation increases [2], which was also proven in realistic scenarios by simulation [1].”
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